The program is an interdisciplinary study of several membrane proteins utilizing in common an electron microscope facility and a laboratory for microsequencing in which the capability for nanomole and subanomole level analyses are being developed. Research will focus on the structure and physiology of gap junctions and their constituent proteins, the nature of protein diversity in transplantation antigens and in the T/t complex so as to provide insight into the organization and evolution of the genes that code for the surface molecules. Work on the glycoproteins of the membranes of the Sindbis virus and their precursors and immunocytological and biochemical analyses of filamentous proteins in muscle and non-muscle cells is being pursued as well as analyses characterizing membrane proteins from cloned murine cell lines derived from UV-induced skin tumors bearing both specific and cross-reactive antigens.